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Full-Text Articles in Engineering
Analysis Of Additively Manufactured Inconel 718 Combustion Behavior In Promoted Oxygen Environments, Dominic George Dieguez
Analysis Of Additively Manufactured Inconel 718 Combustion Behavior In Promoted Oxygen Environments, Dominic George Dieguez
Open Access Theses & Dissertations
Promoted combustion testing is a vital tool for engineers to establish the combustion and flammability characteristics of materials (metallic or otherwise) in oxygen enriched environments. Historically, much of the established data for metallic promoted combustion has been with regards to materials in their cast and wrought forms. However, with the emergence of additive manufacturing as a preferred method of fabrication, the need exists to evaluate how metals in that form behave. Recent testing has demonstrated that even if a metal or alloy is nominally the same with regards to chemistry, flammability between samples in the wrought form can differ significantly …
Sulfonated Styrene Grafted Sebs/Abs Made By Additive Manufacturing For Ion Exchange Applications, Avianna Elaine Gallegos
Sulfonated Styrene Grafted Sebs/Abs Made By Additive Manufacturing For Ion Exchange Applications, Avianna Elaine Gallegos
Open Access Theses & Dissertations
An interpenetrating polymer network (IPN) for cation exchange applications was synthesized from a blend of styrene-ethylene/butylene-styrene (SEBS) and acrylonitrile butadiene styrene (ABS), which was 3D printed, grafted with crosslinked polystyrene (PS), and sulfonated. A method for styrene grafting was applied to reduce the damage to polymer phases caused by the sulfonation reaction. Styrene and divinylbenzene monomers were introduced to the IPN and induced with heat treatment to polymerize in situ. The graft copolymerization reaction was enhanced with varying quantities of benzoyl peroxide as a chemical initiator. The samples were subsequently sulfonated with chlorosulfonic acid in dichloroethane and functionalized for ion …
Material Synthesis And Machine Learning For Additive Manufacturing, Jaime Eduardo Regis
Material Synthesis And Machine Learning For Additive Manufacturing, Jaime Eduardo Regis
Open Access Theses & Dissertations
The goal of this research was to address three key challenges in additive manufacturing (AM), the need for feedstock material, minimal end-use fabrication from lack of functionality in commercially available materials, and the need for qualification and property prediction in printed structures. The near ultraviolet-light assisted green reduction of graphene oxide through L-ascorbic acid was studied with to address the issue of low part strength in additively manufactured parts by providing a functional filler that can strengthen the polymer matrix. The synthesis of self-healing epoxy vitrimers was done to adapt high strength materials with recyclable properties for compatibility with AM …
Suitability Of Low-Cost Additive Manufacturing For Polymer Electrolyte Fuel Cells, David Alexander
Suitability Of Low-Cost Additive Manufacturing For Polymer Electrolyte Fuel Cells, David Alexander
Open Access Theses & Dissertations
The purpose of this dissertation is to study the feasibility of low-cost additive manufacturing to fabricate polymer electrolyte fuel cell bipolar plate materials. Traditional manufacturing techniques include molding, milling, hollow embossing, hydro-forming, rolling, and electromagnetic forming. These processes are employed when a design has been selected due to higher costs at low volumes. The combination of high initial costs and bipolar plates being the most expensive component of the polymer electrolyte fuel cell creates incentive to mitigate this obstacle. The feasibility of low-cost additive manufactured bipolar plates will be proven by fabrication, post-processing, and characterization of printed test specimen. The …
Direct Write 3d Printing Of Functional Ceramics, Jorge Angel Diaz
Direct Write 3d Printing Of Functional Ceramics, Jorge Angel Diaz
Open Access Theses & Dissertations
Humidity sensors are used in many industries and are important for ensuring quality and safety. Ceramic sensors are preferred because of their quick response time, ability to withstand high temperatures and excellent Chemical and mechanical stability. The manufacturing world has been moving toward additive manufacturing which is a form of synthesizing 3D tangible layer by layer in witch minimal waste is produced. Additive manufacturing also is known as 3D printing has opened new possibilities to design engineers by giving them design freedom and access to the layers of a part to allow embedded sensors. There is a category of ceramics …
Investigating Using Titanium Zirconium Molybdenum For Additively Manufacturing Aerospace Components, Justin Hunter Vanhoose
Investigating Using Titanium Zirconium Molybdenum For Additively Manufacturing Aerospace Components, Justin Hunter Vanhoose
Open Access Theses & Dissertations
Mankind throughout history has possessed an innate characteristic to explore, migrating to new frontiers.The requirement for this travel is most broadly associated with the need to pursue more resources. Rockets have been used as a means of weapons since the Sung Dynasty in the thirteenth empire and have now been integrated for travel/transport. The sophistication of rocketry and propulsion has reached a level to where it is plausible that mankind will be a multi-planetary species. The space industry has grown significantly with the advancement of the sophistication of these rocket technologies. However, a specific challenge to overcome in the space …
A New Approach To Multiplanar, Real-Time Simulation Of Physiological Knee Loads And Synthetic Knee Components Augmented By Local Composition Control In Fused Filament Fabrication, Joshua Taylor Green
A New Approach To Multiplanar, Real-Time Simulation Of Physiological Knee Loads And Synthetic Knee Components Augmented By Local Composition Control In Fused Filament Fabrication, Joshua Taylor Green
Open Access Theses & Dissertations
Despite numerous advances in biomedical engineering, few developments in surgical simulation have been made outside of computational models. Cadavers remain the primary media on which surgical research and simulation is conducted. Most attempts to quantify the effects of orthopedic surgical methods fail to achieve statistical significance due to limited quantities of cadaver specimen, large variations among the cadaver population, and a lack of repeatability among measurement techniques. The general purpose of the research covered in this dissertation is to develop repeatable simulation of physiological loads and develop techniques to fabricate a synthetic-based replacement of cadaver specimens. Future work applying this …
Comprehensive Finite Element Modeling Of Ti-6al-4v Cellular Solids Fabricated By Electron Beam Melting, Edel Arrieta
Comprehensive Finite Element Modeling Of Ti-6al-4v Cellular Solids Fabricated By Electron Beam Melting, Edel Arrieta
Open Access Theses & Dissertations
Additive manufacturing permits the fabrication of cellular metals which are materials that can be highly customizable and possess multiple and extraordinary properties such as damage tolerance, metamorphic and auxetic behaviors, and high specific stiffness. This makes them the subject of interest for innovative applications. With interest in these materials for energy absorption applications, this work presents the development of nonlinear finite element models in commercial software platforms (MSC Patran/Nastran) that permit the analysis of the deformation mechanisms of these materials under compressive loads. In the development of these models, a detailed multiscale study on the different factors affecting the response …
Effects Of Fabrication Conditions On Mechanical Properties Of Ti-6al-4v Fabricated By Powder Bed Fusion Additive Manufacturing, Paola Azani
Open Access Theses & Dissertations
At the writing of this Thesis, additive manufacturing (AM) also known as 3D printing, has been popularized for its diversity in applications ranging from home and personal use, medical, industrial, consumer products, aerospace, architecture, automotive, military, fashion, food, art and more. Industries taking advantage of the design freedom and complexity offered by AM have exploded the growth of the technologies. Specifically, technologies that process metals using electron and laser beams have been recognized by the aerospace industry as a promising avenue for re-engineered components leading to reduced weight and improved engineering efficiencies for components like engine brackets and nozzles. However, …
Reducing Metal Alloy Powder Costs For Use In Powder Bed Fusion Additive Manufacturing: Improving The Economics For Production, Fransisco Medina
Reducing Metal Alloy Powder Costs For Use In Powder Bed Fusion Additive Manufacturing: Improving The Economics For Production, Fransisco Medina
Open Access Theses & Dissertations
Titanium and its associated alloys have been used in industry for over 50 years and have become more popular in the recent decades. Titanium has been most successful in areas where the high strength to weight ratio provides an advantage over aluminum and steels. Other advantages of titanium include biocompatibility and corrosion resistance. Electron Beam Melting (EBM) is an additive manufacturing (AM) technology that has been successfully applied in the manufacturing of titanium components for the aerospace and medical industry with equivalent or better mechanical properties as parts fabricated via more traditional casting and machining methods. As the demand for …
The Influence Of Build Parameters On The Microstructure During Electron Beam Melting Of Ti6al4v, Karina Puebla
The Influence Of Build Parameters On The Microstructure During Electron Beam Melting Of Ti6al4v, Karina Puebla
Open Access Theses & Dissertations
With the demand of devices to replace or improve areas, such as: electronic, biomedical and aerospace industries. Improvements in these areas of engineering have been in need due to the customer’s needs for product properties requirements. The design of components must exhibit better material properties (mechanical or biocompatible) close to those of any given product. Rapid prototyping (RP) technologies that were originally designed to build prototypes may now be required to build functional end-use products. To carry out the transition, from RP to rapid manufacturing (RM), the available materials utilized in RP must provide the performance required for RM. The …
Microstructural Architecture Developed In The Fabrication Of Solid And Open-Cellular Copper Components By Additive Manufacturing Using Electron Beam Melting, Diana Alejandra Ramirez
Microstructural Architecture Developed In The Fabrication Of Solid And Open-Cellular Copper Components By Additive Manufacturing Using Electron Beam Melting, Diana Alejandra Ramirez
Open Access Theses & Dissertations
The fabrication of Cu components were first built by additive manufacturing using electron beam melting (EBM) from low-purity, atomized Cu powder containing a high density of Cu2O precipitates leading to a novel example of precipitate-dislocation architecture. These microstructures exhibit cell-like arrays (1-3µm) in the horizontal reference plane perpendicular to the build direction with columnar-like arrays extending from ~12 to >60 µm in length and corresponding spatial dimensions of 1-3 µm. These observations were observed by the use of optical metallography, and scanning and transmission electron microscopy. The hardness measurements were taken both on the atomized powder and the Cu components. …